Prospective association of dietary soy and fibre intake with puberty timing: a cohort study among Chinese children.

BACKGROUND: Dietary phytoestrogens have been suggested to influence puberty timing, a critical stage for well-being in adulthood. We hypothesized that childhood soy intake might prospectively influence puberty timing and that dietary fibre and the key isoflavone metabolite equol might play roles. METHODS: Cox proportional hazard regression models were performed in 4781 children (2152 girls and 2629 boys) aged 6-8 years old from the Chinese Adolescent Cohort Study for whom a food frequency questionnaire at baseline and information about potential confounders were available. Anthropometry and pubertal status including age at Tanner stage 2 for breast development (B2) or age at the initiation of gonadal growth (G2), and age at menarche (M) or voice break (VB) were assessed annually. Equol excretion was determined by urine samples from 1311 participants. RESULTS: Among girls and boys, higher soy intake was associated with later puberty timing (hazard ratio (HR)-B2: 0.88 (95% CI, 0.80-0.96), p=0.02; HR-M, 0.87 (0.77-0.94), p=0.01; HR-G2, 0.91 (0.82-0.98), p=0.013; HR-VB, 0.90 (0.82-0.9), p=0.02), independent of prepubertal body fatness and fibre intake. These associations were more pronounced among children with a high urinary equol level (pfor-interaction ≤ 0.04) or with a high cereal fibre intake (pfor-interaction ≤ 0.06). Intake of dietary fibre or its subtype was not prospectively associated with puberty onset after adjusting for dietary soy intake (p≥0.06). CONCLUSION: Higher childhood soy intake is prospectively associated with later puberty timing in both Chinese girls and boys, independent of prepubertal body fatness, and the association is particularly pronounced among individuals with a higher urinary equol level.

Urinary and salivary endocrine measurements to complement Tanner staging in studies of pubertal development.

BACKGROUND: Many studies investigating pubertal development use Tanner staging to assess maturation. Endocrine markers in urine and saliva may provide an objective, sensitive, and non-invasive method for assessing development. OBJECTIVE: Our objective was to examine whether changes in endocrine levels can indicate the onset of pubertal development prior to changes in self-rated Tanner stage. METHODS: Thirty-five girls and 42 boys aged 7 to 15 years were enrolled in the Growth and Puberty (GAP) study, a longitudinal pilot study conducted from 2007-2009 involving children of women enrolled in the Agricultural Health Study (AHS) in Iowa. We collected saliva and urine samples and assessed pubertal development by self-rated Tanner staging (pubic hair, breast development (girls), genital development (boys)) at three visits over six months. We measured dehydroepiandrosterone (DHEA) in saliva and creatinine-adjusted luteinizing hormone (LH), testosterone, follicle stimulating hormone (FSH), estrone 3-glucuronide (E13G) and pregnanediol 3-glucuronide (Pd3G) concentrations in first morning urine. We evaluated the relationships over time between Tanner stage and each biomarker using repeated measures analysis. RESULTS: Among girls still reporting Tanner breast stage 1 at the final visit, FSH levels increased over the 6-month follow-up period and were no longer lower than higher stage girls at the end of follow-up. We observed a similar pattern for testosterone in boys. By visit 3, boys still reporting Tanner genital stage 1 or pubic hair stage 1 had attained DHEA levels that were comparable to those among boys reporting Tanner stages 2 or 3. CONCLUSIONS: Increasing concentrations of FSH in girls and DHEA and testosterone in boys over a 6-month period revealed the start of the pubertal process prior to changes in self-rated Tanner stage. Repeated, non-invasive endocrine measures may complement the more subjective assessment of physical markers in studies determining pubertal onset.

Clinical utility of urinary gonadotrophins in hypergonadotrophic states as Turner syndrome.

Background Girls with Turner syndrome (TS) are at an increased risk of primary ovarian insufficiency (POI). Good correlation between serum and urinary gonadotrophins exists in children assessed for disorders of puberty, but there is little evidence of their reliability in hypergonadotropic states. Objectives To determine whether there was a correlation between serum and urinary Luteinising Hormone (uLH) and Follicle-Stimulating Hormone (uFSH) in hypergonadotrophic states, and whether uFSH could suggest an ovarian failure in TS as Anti-Mullerian Hormone (AMH). Patients and Methods Retrospective cohort study of 37 TS girls attending the paediatric TS clinic in Glasgow between February 2015 and January 2019, in whom 96 non-timed spot urine samples were available with a median age at time of sample of 12.89 years (3.07-20.2 years). uLH and uFSH were measured by chemiluminescent microparticle immunoassay. Simultaneous serum gonadotrophins and AMH were available in 30 and 26 girls, respectively. AMH <4 pmol/L was considered indicative of ovarian failure. Results A strong correlation was found between serum LH and uLH (r 0.860, P<0.001) and serum FSH and uFSH (r 0.905, p<0.001). Among patients≥10 years not on oestrogen replacement, ROC curve identified uFSH as a reasonable marker for AMH<4 pmol/L uFSH of >10.85 U/L indicates an AMH <4 pmol/L with 75% sensitivity and 100 % specificity (AUC 0.875)with similar ability as serum FSH (AUC 0.906). Conclusion uLH and uFSH are non-invasive, useful and reliable markers of ovarian activity in hypergonadotropic states as TS. uFSH could provide an alternative to AMH (in centres which are limited by availability or cost) in revealing ovarian failure and requirement for oestrogen replacement in pubertal induction.

Influence of pubertal development on urinary oxidative stress biomarkers in adolescent girls in the New York LEGACY cohort.

Puberty is a time of intense growth and differentiation of breast tissue and a window of susceptibility (WOS) for breast cancer. Although oxidative stress markers have been associated with breast cancer risk, it is unclear whether oxidative stress levels are different during the pubertal WOS, and if so, whether these differences are related to breast cancer susceptibility. We measured urinary biomarkers of whole body oxidative stress (urinary F2-Isoprostanes and 8-oxodeoxyguanosine (8-oxodG)) in 158 girls (ages 6-13 years), 71 with and 87 without a breast cancer family history (BCFH) from a cohort of adolescent girls from the New York site of the LEGACY cohort (Lessons in Epidemiology and Genetics in Adults Cancer from Youth). We compared levels of urinary oxidative stress biomarkers (F2-Isoprostanes and 8-oxodG) across the pubertal window, defined by Tanner Stage (TS) of breast development, both cross-sectionally and longitudinally within girls over an 18-month follow up period. Urinary oxidative stress biomarkers were unrelated to pubertal stages in cross-sectional analyses after considering adjustments for body mass index (BMI) and BCFH. In our longitudinal analysis, we found that urinary 8-oxodG levels, but not F2-Isoprostane levels, increased with age in BCFH + girls (ß = 6.12, 95% CI = 0.08-12.16) compared to BCFH-girls. Higher BMI was associated with higher level of F2-Isoprostane in both cross-sectional (ß = 0.02, 95% CI = 0.0004-0.05) and longitudinal analysis (ß = 0.02, 95% CI = 0.0002-0.05). These findings support that higher BMI increases oxidative stress biomarkers over the pubertal window and that there are changes in 8-oxodG oxidative stress biomarkers in girls with a BCFH compared to girls without a BCFH.

Random urinary gonadotropins as a useful initial test for girls with central precocious puberty.

Recent evidence indicates that urinary gonadotropins may be an alternative method for detecting pubertal disorders. The aim of this study was to evaluate the associations of first morning voided (FMV) and random urinary gonadotropins with the pubertal response to a gonadotropin-releasing hormone (GnRH) stimulation test to determine whether random urinary gonadotropins can be used as an alternative method for evaluating central precocious puberty (CPP). In total, 100 girls aged 6.0-8.9 years were enrolled. The subjects were divided into two groups according to their pubertal response to the GnRH stimulation test: a positive group (n = 68) and a negative group (n = 32). Random urinary luteinizing hormone (LH), follicle-stimulating hormone (FSH), and the LH:FSH ratio were significantly positively correlated with FMV urinary LH (r = 0.411, p < 0.001), FMV urinary FSH (r = 0.494, p < 0.001), and the FMV urinary LH:FSH ratio (r = 0.519, p < 0.001). The optimal cutoff values from receiver operating characteristic (ROC) curve analyses were determined to be 0.20 IU/L for random urinary LH (area under the curve (AUC) of 0.812, p < 0.001), 3.03 IU/L for random urinary FSH (AUC of 0.670, p = 0.004) and 0.08 for the random urinary LH:FSH ratio (AUC of 0.784, p < 0.001). No differences were observed between FMV and random urinary LH (p = 0.827), between FMV and random urinary FSH (p = 0.650), or between the FMV and random urinary LH:FSH ratio (p = 0.688) in ROC curve analyses with DeLong's test. Based on our findings, random urinary gonadotropins may be applicable in clinical practice as a useful initial test for girls with CPP.

Bisphenol A and pubertal height growth in school-aged children.

BACKGROUND: Bisphenol A (BPA) is an environmental endocrine disruptor and is found in many consumer products. Studies suggest that BPA may perturb pubertal development, although evidence on BPA-influenced pubertal height growth is scarce. METHODS: A total of 754 children aged 9-18 years from three schools (one elementary, one middle, and one high school) in Shanghai were included in this longitudinal study. Height was measured at enrolment (visit 1) and, subsequently, at 19 months after enrolment (visit 2). Age- and sex-specific Z scores for height were calculated (height Z score = [participant's height-sex- and age-specific population height mean]/sex- and age-specific population height standard deviation). Urine samples were collected at enrolment to measure BPA concentrations. We used multiple linear regression models or general estimating equation models (GEE) to estimate associations between urine BPA level and height Z score. RESULTS: The geometric mean of urine BPA concentrations was 1.6 µg/L (95%CI: 1.4, 1.8) or 1.2 µg/g creatinine (95%CI: 1.0, 1.3). An inverse association between urine BPA level and height was observed in boys. After adjustment for potential confounders, height Z score at enrolment in boys decreased by 0.49 for the highest exposure level (above 10.9 µg/g creatinine as the 90th percentile), compared with the lowest BPA exposure (below 0.2 µg/g creatinine as the 25th percentile) (95%CI: -0.96, -0.01; p-trend = 0.024). The inverse association remained between BPA exposure and height Z score at visit 2. The GEE model showed that a 1-unit increase in log10-transformed BPA concentrations was associated with a 0.15-point decrease in height Z score over the follow-up (95%CI: -0.30, -0.01). BPA was not associated with height growth in girls. CONCLUSIONS: Our findings indicate an inverse association between urine BPA level and height growth in boys. These findings need to be confirmed in further studies.

Ovarian hormones, age and pubertal development and their association with days of headache onset in girls with migraine: An observational cohort study.

Background Fifty-three percent of adolescent girls report headaches at the onset of menses, suggesting fluctuations of ovarian hormones trigger migraine during puberty. Aims To determine if urinary metabolites of estrogen and progesterone are associated with days of headache onset (HO) or severity in girls with migraine. Methods This was a pilot study and included 34 girls with migraine balanced across three age strata (pre-pubertal (8-11), pubertal (12-15), and post-pubertal (16-17) years of age). They collected daily urine samples and recorded the occurrence and severity of headache in a daily diary. Urine samples were assayed for estrone glucuronide (E1G) and pregnandiol glucuronide (PdG) and the daily change was calculated (ΔE1G, ΔPdG). Pubertal development was assessed by age, pubertal development score (PDS), and menstrual cycle variance. The primary outcome measures were HO days and headache severity. Generalized linear mixed models were used, and included the hormonal variables and three different representations of pubertal development as covariates. Results Models of HO days demonstrate a significant age*PdG interaction (OR 0.85 [95% CI 0.75, 0.97]) for a 1 standard deviation increase in PdG and three-year increase in age. A separate model showed a significant PDS*PdG interaction (OR -0.85 [95% CI; 0.76, 0.95]). ΔPDG was associated with headache severity in unadjusted models ( p < 0.017). Conclusion Age and pubertal development could moderate the effect of ovarian hormones on days of headache onset in girls with migraine.

Pre-pubertal exposure with phthalates and bisphenol A and pubertal development.

OBJECTIVE: Epidemiological studies indicate associations between childhood exposure with phthalates and bisphenol A (BPA) and the pubertal development. We examined associations between the pre-pubertal phthalate and BPA body burden and the longitudinally assessed sexual maturation of eight- to thirteen-year-old children. METHODS: We started with eight- to ten-year-old children in the baseline study and quantified phthalate metabolites and BPA in 472 urine samples (250 boys; 222 girls; mean age: 8.8 years). Associations between the pubertal development, assessed in three annual follow-up studies by Puberty Development scale questionnaires (PD scales), and the chemical exposure from the baseline visit were longitudinally analyzed with generalized estimation equations. RESULTS: The number of children with both chemical measures and PD scores (calculated from the PD scales) was 408. In the third follow-up, 49% of the girls and 18% of the boys had reached mid-puberty. For girls, we observed a delayed pubertal development with the di-hexyl-ethyl phthalate (DEHP) metabolites (ß: -0.16 to -0.23; p ≤ 0.05 or p ≤ 0.1), mono-n-butyl phthalate (ß: -0.15; 95% CI: -0.31; 0.01), mono-benzyl phthalate (ß: -0.11; 95% CI: -0,24; -0,01), and mono-ethyl phthalate (MEP) (ß: -0.15; 95% CI: -0.28; -0.01). In addition, significant non-linear associations of the DEHP metabolites and BPA with the PD scores were found, when their quadratic effects were included in the GEE models. In boys, no consistent relationships between the PD scores and the chemicals were detected except of an accelerated development with the ∑DEHP metabolites (ß: 0.16; 95% CI: -0.02; -0.34). CONCLUSION: We found indications that pre-pubertal exposures with phthalates and BPA were associated with pubertal timing in children, particularly in girls. For boys, associations were inconsistent, and not necessarily in line with the known anti-androgenicity of some phthalates during prenatal exposure.

Nocturnal Urinary Excretion of FSH and LH in Children and Adolescents With Normal and Early Puberty.

Context: Clinical use of single serum gonadotropin measurements in children is limited by the pulsatile secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). However, first morning voided (FMV) urine may integrate the fluctuating gonadotropin serum levels. Objective: We aimed to evaluate urinary and serum gonadotropin levels according to age, sex, and pubertal stage in healthy children and to assess the clinical use of FMV urinary gonadotropins in children with disordered puberty. Design: Cross-sectional part of the COPENHAGEN Puberty Study and longitudinal study of patients. Setting: Population-based and outpatient clinic. Patients or Other Participants: Eight hundred forty-three healthy children from the COPENHAGEN Puberty Study and 25 girls evaluated for central precocious puberty (CPP). Main Outcome Measures: Clinical pubertal staging, including serum and urinary gonadotropin levels. Results: Urinary gonadotropins increased with advancing age and pubertal development and were detectable in FMV urine before physical signs of puberty. FMV urinary LH correlated strongly with basal (r = 0.871, P < 0.001) and gonadotropin-releasing hormone (GnRH)-stimulated serum LH (r = 0.82, P < 0.001). Urinary LH was superior to urinary FSH in differentiating the pubertal stage. Receiver operating curve analysis revealed that a cut-off standard deviation (SD) score of 2 for urinary LH (IU/L) gave a sensitivity of 75% and a specificity of 92% in predicting a positive GnRH stimulation test (LHmax > 5 IU/L). Urinary concentrations of LH decreased after 3 months of GnRH treatment to levels below +2 SDs. Conclusions: Urinary gonadotropin levels increased before the onset of puberty and were elevated in girls with CPP. We suggest urinary LH as an alternative noninvasive method to improve diagnosing and therapeutic management of children with disordered puberty.

Urine bisphenol A and pubertal development in boys.

BACKGROUND: Bisphenol A (BPA) is an environmental endocrine disruptor and is found in many consumer products. Animal studies suggest that BPA may perturb pubertal development in males, although studies in humans are limited. OBJECTIVE: This study investigated the association between BPA exposure and pubertal onset and progression among school-aged boys in Shanghai, China. METHODS: A total of 671 boys aged 9-18 years from three schools (one elementary, one middle, and one high school) in Shanghai were enrolled in a cross-sectional study. Tanner stages for genital and pubic hair development and testicular volume were assessed by a specifically trained physician. Information concerning spermarche was self-reported. Urine samples were collected to examine peripubertal BPA exposure levels. Associations between BPA exposure and pubertal development, as indicated by the presence of different milestones in early puberty, mid-puberty and late puberty, were assessed using Poisson multivariate regression to derive adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs). RESULTS: Earlier onset of genital and pubic hair development was observed in boys with moderate BPA exposure compared with those exposed to the least BPA; the adjusted PRs were 1.31 (95%CI:1.03, 1.68) and 1.28 (95%CI:1.02, 1.60) for onset of genital maturation and pubic hair development, respectively. A similar trend was seen for onset of testicular development, although the association was not statistically significant. Conversely, compared with the lowest level of BPA exposure, moderate BPA exposure was associated with delayed presence of the late stage of genital development, with an adjusted PR of 0.78 (95%CI: 0.65, 0.92). A suggestive inverse association was also observed between BPA exposure and late progression of testicular development. CONCLUSIONS: Our findings indicate an association between peripubertal BPA exposure and earlier pubertal onset, but delayed pubertal progression, in boys. Longitudinal studies of male pubertal development with periodic follow-up are needed to verify these results.

The measurement of urinary gonadotropins for assessment and management of pubertal disorder.

OBJECTIVE: Measurement of urinary LH (uLH) and FSH (uFSH) may facilitate non-invasive pubertal assessment but there is a need for further validation by studying children and adolescents with disorders of puberty. DESIGN: 65 cases (Male: 25) with a median age of 12 years (2.9-18.1) supplied at least one non-timed urine sample for uLH and uFSH measurement by immunoassay and corrected for creatinine excretion. 25 cases were receiving GnRH-agonist (GnRH-a) at the time of sample collection. In 41 cases, urine samples were collected prior to a LHRH test and in 12 cases matched serum samples for basal LH (sLH) and FSH (sFSH) were also available. RESULTS: There was a significant correlation between sLH and uLH:uCr (r=0.82; p-value <0.001) and sFSH and uFSH:uCr (r=0.93; p-value <0.001). Based on receiver operator characteristics analysis, a uLH:uCr value of 0.05 IU/mmol as a cut-off would detect a LH peak >5U I/L with a sensitivity of 86% and a specificity of 72% with a positive predictive value of 93%. In pubertal boys (6) and girls (22) with a sLH peak >5UI/L, median uLH:uCr was 0.27 IU/mmol (0.27-0.28) and 0.17 IU/mmol (0.09-0.43), respectively. The median uFSH:uCr was 0.51 IU/mmol (0.41-0.60) for boys and 1.1 IU/mmol (0.21-2.44) for girls. In the 25 cases on GnRH-a, the median uLH:uCr for boys and girls was 0.02 IU/mmol (0.01-0.02) and 0.02 IU/mmol (0.004-0.07), respectively, and the median uFSH:uCr was 0.07 IU/mmol (0.05-0.09) and 0.27 IU/mmol (0.09-0.54), respectively. CONCLUSION: Urinary gonadotrophins reflect serum gonadotrophin concentration and may represent a reliable non-invasive method of assessing pubertal progress.

Serum and urine insulin-like growth factor-1 as biochemical growth maturity indicators.

INTRODUCTION: Biochemical markers are agents directly involved in bone growth and remodeling and can be quantitatively evaluated from various biologic fluids. The aim of this study was to assess the changes in the levels of insulin-like growth factor-1 (IGF-1) in serum and urine as a growth maturity indicator and to compare them with the cervical vertebral maturation radiographic stages. METHODS: The study was conducted with 72 female subjects aged 8 to 20 years. Cervical vertebral maturation stages, and serum and urine IGF-1 levels were recorded for all subjects, and the subjects were equally divided into the 6 cervical vertebral maturation groups. Median values of IGF-1 for each stage of cervical vertebral maturation were calculated and statistically compared with those of the other stages. RESULTS: The levels of serum and urine IGF-1 at stage 4 of cervical vertebral maturation were significantly higher than those from the other stages (P <0.01). Stage 4 corresponded to a mean age of 13.67 years. A significant correlation was observed between serum and urine IGF-1 (P <0.001). CONCLUSIONS: Urine IGF-1 follows the growth curve similar to serum IGF-1. Thus, urine IGF-1 may be regarded as a promising noninvasive tool for growth assessment. Further research is necessary to validate these results in a different population and with a larger sample.

First Morning Voided Urinary Gonadotropin Measurements as an Alternative to the GnRH Test.

AIMS: We studied whether first morning voided (FMV) urinary gonadotropin measurements could be used as a noninvasive alternative to the GnRH test in the assessment of the hypothalamic-pituitary-gonadal function in children. METHODS: In a single-center study, we compared FMV urinary gonadotropin concentrations with basal and GnRH-stimulated serum gonadotropin levels in 274 children and adolescents (78 girls, 196 boys) aged 5-17 years referred for growth and pubertal disorders. The concordance between FMV urinary gonadotropin concentrations and GnRH test results was assessed. RESULTS: FMV urinary LH (U-LH), urinary FSH (U-FSH) and their ratios correlated well with the corresponding basal and GnRH-stimulated serum parameters (r ≥ 0.66, p < 0.001). Receiver operating characteristic curve analyses using urinary and serum LH and FSH concentrations showed that FMV U-LH and U-LH/U-FSH performed equally well as the GnRH test in the differentiation of early puberty (Tanner stage 2) from prepuberty (Tanner stage 1) (area under the curve 0.768-0.890 vs. 0.712-0.858). FMV U-LH and U-LH/U-FSH performed equally well as basal serum LH in predicting a pubertal GnRH test result (area under the curve 0.90-0.93). CONCLUSION: FMV U-LH determination can be used for the evaluation of pubertal development and its disorders, reducing the need for invasive GnRH stimulation tests.

Urinary Sex Steroids and Anthropometric Markers of Puberty - A Novel Approach to Characterising Within-Person Changes of Puberty Hormones.

BACKGROUND/AIMS: The longitudinal relationships of within-individual hormone and anthropometric changes during puberty have not ever been fully described. The objectives of this study were to demonstrate that 3 monthly urine collection was feasible in young adolescents and to utilise liquid chromatography-tandem mass spectrometry assay methods for serum and urine testosterone (T), estradiol (E2) and luteinizing hormone (LH) in adolescents by relating temporal changes in urine and serum hormones over 12 months to standard measures of pubertal development. METHODS: A community sample of 104 adolescents (57 female) was studied over 12 months with annual anthropometric assessment, blood sampling and self-rated Tanner staging and urine collected every 3 months. Serum and urine sex steroids (T, E2) were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and LH by immunoassay. RESULTS: A high proportion (92%) of scheduled samples were obtained with low attrition rate of 6.7% over the 12 months. Urine hormone measurements correlated cross-sectionally and longitudinally with age, anthropometry and Tanner stage. CONCLUSION: We have developed a feasible and valid sampling methodology and measurements for puberty hormones in urine, which allows a sampling frequency by which individual pubertal progression in adolescents can be described in depth.

Cadmium delays puberty onset and testis growth in adolescents.

OBJECTIVE: Cadmium (Cd) has been shown to impair pubertal development in experimental animals. However, no data are available for male adolescents with increased urinary cadmium levels. DESIGN: The aim of this cross-sectional study was to evaluate pubertal onset and pituitary-gonadal axis hormones in male adolescents with increased urinary levels of Cd. SUBJECTS: We studied 111 males, aged 12-14 years living in the Milazzo-Valle del Mela area. A control age-matched population (n = 60) living 28-45 km far from the industrial site was also enrolled. MEASUREMENTS: Pubertal stages were assessed by clinical examination according to Tanner's score. Mean testicular volume was also investigated by ultrasound examination. Urinary Cd concentration and blood levels of FSH, LH, testosterone and inhibin B were also investigated. RESULTS: Cd levels were significantly higher in adolescents living in the Milazzo-Valle del Mela area, compared to both age-matched subjects living far from the industrial plants and the reference values. Our population showed also a delayed onset of puberty, a smaller testicular volume and lower testosterone levels. An inverse correlation was found between urinary Cd and testicular volume (r = -0·25; P = 0·0008), testosterone levels (Spearman's r = -0·0·37; two-tailed P < 0·0001) and LH levels (Spearman's r = 0·048; P < 0·05). Testosterone levels were positively correlated with testicular volume (Spearman's r = 0·48; P < 0·0001). CONCLUSIONS: This study, for the first time, suggests that increased Cd burden is associated with delayed onset of puberty in male adolescents and impaired testicular growth.

Gender differences in cadmium and cotinine levels in prepubertal children.

Susceptibility to environmental stressors has been described for fetal and early childhood development. However, the possible susceptibility of the prepubertal period, characterized by the orchestration of the organism towards sexual maturation and adulthood has been poorly investigated and exposure data are scarce. In the current study levels of cadmium (Cd), cotinine and creatinine in urine were analyzed in a subsample 216 children from 12 European countries within the DEMOCOPHES project. The children were divided into six age-sex groups: boys (6-8 years, 9-10 years and 11 years old), and girls (6-7 years, 8-9 years, 10-11 years). The number of subjects per group was between 23 and 53. The cut off values were set at 0.1 µg/L for Cd, and 0.8 µg/L for cotinine defined according to the highest limit of quantification. The levels of Cd and cotinine were adjusted for creatinine level. In the total subsample group, the median level of Cd was 0.180 µg/L (range 0.10-0.69 µg/L), and for cotinine the median wet weight value was 1.50 µg/L (range 0.80-39.91 µg/L). There was no significant difference in creatinine and cotinine levels between genders and age groups. There was a significant correlation between levels of cadmium and creatinine in all children of both genders. This shows that even at such low levels the possible effect of cadmium on kidney function was present and measurable. An increase in Cd levels was evident with age. Cadmium levels were significantly different between 6-7 year old girls, 11 year old boys and 10-11 year old girls. As there was a balanced distribution in the number of subjects from countries included in the study, bias due to data clustering was not probable. The impact of low Cd levels on kidney function and gender differences in Cd levels needs further investigation.

Urinary phthalates from 168 girls and boys measured twice a year during a 5-year period: associations with adrenal androgen levels and puberty.

BACKGROUND: Little is known about the possible deleterious effects of phthalate exposure on endogenous sex steroid levels in children. OBJECTIVE: Our objective was to investigate whether urinary phthalate metabolite levels are associated with circulating adrenal androgen levels and age at puberty. METHODS: This was a longitudinal study of 168 healthy children (84 girls) examined every 6 months for 5 years. Serum levels of dehydroepiandrostenedione sulfate (DHEAS), Δ4-androstenedione, testosterone, and urinary morning excretion of 14 phthalate metabolites, corresponding to 7 different phthalate diesters were determined. A variation in urinary excretion of phthalates was evident in each child, which made a mean of repetitive samples more representative for long-term excretion than a single determination. RESULTS: We found that girls with excretion of monobutyl phthalate isomers (MBP) and di(2-ethylhexyl) phthalate metabolites above the geometric group mean (795 and 730 ng/kg, respectively) had lower levels of DHEAS and Δ4-androstenedione, although statistically significant only at 13 years of age. In boys, we found that excretion of monobenzyl phthalate above the geometric group mean (346 ng/kg) was associated with lower levels of DHEAS at 11 years of age but higher levels of testosterone at 13 years of age. The same trend was observed for MBP excretion, albeit not statistically significant. A lower age at pubarche was observed in boys with excretion of MBP above the geometric group mean (11.0 vs 12.3 years, P = 0.005). CONCLUSION: Our data indicate that exposure to dibutyl phthalate isomers (DBP) (in girls) and butylbenzyl phthalate (in boys) are negatively associated with adrenal androgen levels and in boys positively associated with testosterone level at 13 years of age. High exposure to DBP was associated with earlier age at pubarche in boys. In girls, no associations between phthalate exposure and age at pubertal milestones were observed.

Methodological considerations in use of the cortisol/DHEA(S) ratio in adolescent populations.

OBJECTIVE: The cortisol/DHEA(S) ratio has demonstrated utility in studies of HPA activity and psychopathology. However, use of the cortisol/DHEA(S) ratio in adolescent populations requires additional consideration of differential changes in DHEA(S) and cortisol during the course of puberty. This study examines the relationship between pubertal status and individual cortisol and DHEAS levels as well as with the cortisol/DHEAS ratio. METHOD: Morning salivary cortisol and urinary DHEAS levels were obtained for 267 young adolescents at three time points, each approximately one year apart. Growth curve modeling and repeated measures ANOVA were used to assess the effect of adrenal development on individual hormone levels and on the total ratio. RESULTS: Pubic hair development was a significant predictor of change over time in DHEAS but not cortisol. Development was also a significant predictor of the cortisol/DHEAS ratio when raw cortisol and DHEAS values were used. CONCLUSIONS: Our findings indicate that, when DHEAS levels were adjusted to control for pubertal status, the ratio demonstrated stability over time. This finding is in line with the hypothesis that the ratio may tap stable individual differences in HPA functioning.

Prepubertal glucocorticoid status and pubertal timing.

CONTEXT: Whether prepubertal glucocorticoid status impacts on the timing of puberty is not clear. OBJECTIVE: The objective of the study was to examine the relationship between prepubertal glucocorticoid status and early or late pubertal markers, independent of adrenarchal and nutritional status. DESIGN AND PARTICIPANTS: Prospective cohort study of healthy Caucasian children (n = 111, 56 boys) who provided both 24-h urine samples and weighed dietary records 1 and 2 yr before the start of pubertal growth spurt [age at take-off (ATO)]. MEASUREMENTS: Major urinary glucocorticoid and androgen metabolites determined by gas chromatography-mass spectrometry analysis were summed to assess daily overall cortisol (ΣC21) and adrenal androgen secretion; urinary free cortisol and cortisone measured by RIA were summed (UFF+UFE) as an indicator of potentially bioactive free glucocorticoids. MAIN OUTCOMES: The main outcomes included ATO, age at peak height velocity, age at menarche/voice break, ages at Tanner stage 2 for breast (girls) and genital (boys) development, and pubic hair. RESULTS: In girls ΣC21, but not UFF+UFE, was associated with pubertal markers after adjusting for overall adrenal androgen, urinary nitrogen, and body fat. Girls with higher ΣC21 (fourth quartile) reached ATO 0.7 yr (P = 0.01) and menarche 0.9 yr later (P = 0.006) than girls with lower ΣC21 (first quartile). The ΣC21 tended to be also positively associated with age at Tanner stage 2 for breast (P = 0.1), Tanner stage 2 for pubic hair (P = 0.1), and age at peak height velocity (P = 0.06). In boys, neither the ΣC21 nor UFF+UFE was related to pubertal timing. CONCLUSION: An individually higher prepubertal glucocorticoid secretion level, even in physiological range, appears to delay early and late pubertal timing of healthy girls, particularly their onset of pubertal growth spurt and menarche.

Prepubertal urinary estrogen excretion and its relationship with pubertal timing.

Whether prepubertal estrogen production impacts on the timing of puberty is not clear. We aimed to investigate prepubertal 24-h estrogen excretion levels and their association with early and late pubertal markers. Daily urinary excretion rates of estrogens of 132 healthy children, who provided 24-h urine samples 1 and 2 yr before the start of the pubertal growth spurt [age at takeoff (ATO)], were quantified by stable isotope dilution/GC-MS. E-sum3 (estrone + estradiol + estriol) was used as a marker for potentially bioactive estrogen metabolites and E-sum5 (E-sum3 + 16-epiestriol + 16-ketoestradiol) for total estrogen production. Pubertal outcomes were ATO, age at peak height velocity (APHV), duration of pubertal growth acceleration (APHV-ATO), age at Tanner stage 2 for pubic hair (PH2), genital (G2, boys) and breast (B2, girls) development, and age at menarche. Prepubertal urinary estrogen excretions (E-sum3 and E-sum5) were not associated with ATO, APHV, and age at PH2 but with duration of pubertal growth acceleration (P < 0.01) in both sexes. Girls with higher E-sum3 reached B2 0.9 yr (P = 0.04) and menarche 0.3 yr earlier (P = 0.04) than girls with lower E-sum3. E-sum3 was not associated with age at G2 in boys (P = 0.6). For most pubertal variables, the associations with E-sum3 were stronger than with E-sum5. In conclusion, prepubertal estrogens may not be critical for the onset of the pubertal growth spurt but are correlated with its duration in both boys and girls. Prepubertal estrogen levels may already predict the timing of girls' menstruation and breast development but do not appear to affect sexual maturation in boys.